💥 Refactor add-hook! macro & change arg order

This update may potentially break your usage of add-hook! if you pass
the :local or :append properties to it. This is how they used to work:

  (add-hook! :append 'some-mode-hook #'do-something)

Thsoe properties must now follow the hooks, e.g.

  (add-hook! 'some-mode-hook :append #'do-something)

Other changes:
- Various add-hook calls have been renamed to add-hook! because I
  incorrectly assumed `defun` always returned its definition's symbol,
  when in fact, its return value is "undefined" (so sayeth the
  documentation). This should fix #1597.
- This update adds the ability to add multiple functions to hooks
  without a list:

    (add-hook! 'some-mode-hook
               #'do-something
               #'do-something-else)

- The indentation logic has been changed so that consecutive function
  symbols at indented at the same level as the first argument, but forms
  are indent like a defun.

    (add-hook! 'some-mode-hook
               #'do-something
               #'do-something-else)

    (add-hook! 'some-mode-hook
      (message "Hello"))

modules/lang/org/contrib/present.el

@@ -36,9 +36,9 @@
         :n [left]  #'org-tree-slide-move-previous-tree)
 
   (add-hook! 'org-tree-slide-mode-after-narrow-hook
-    #'(+org-present-detect-slide-h
-       +org-present-add-overlays-h
-       org-display-inline-images))
+             #'+org-present-detect-slide-h
+             #'+org-present-add-overlays-h
+             #'org-display-inline-images)
 
   (add-hook 'org-tree-slide-mode-hook #'+org-present-init-org-tree-window-h)
   (advice-add #'org-tree-slide--display-tree-with-narrow